From patchwork Tue May 17 09:05:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Penny Zheng X-Patchwork-Id: 12852152 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8B54CC433F5 for ; Tue, 17 May 2022 09:06:34 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.330611.554042 (Exim 4.92) (envelope-from ) id 1nqt9r-0007el-Jk; Tue, 17 May 2022 09:06:23 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 330611.554042; Tue, 17 May 2022 09:06:23 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1nqt9r-0007ee-Fd; Tue, 17 May 2022 09:06:23 +0000 Received: by outflank-mailman (input) for mailman id 330611; Tue, 17 May 2022 09:06:22 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1nqt9p-0006FZ-Up for xen-devel@lists.xenproject.org; Tue, 17 May 2022 09:06:22 +0000 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by se1-gles-sth1.inumbo.com (Halon) with ESMTP id 9dedc3ff-d5c0-11ec-bd2c-47488cf2e6aa; Tue, 17 May 2022 11:06:20 +0200 (CEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 466D41063; Tue, 17 May 2022 02:06:20 -0700 (PDT) Received: from a011292.shanghai.arm.com (a011292.shanghai.arm.com [10.169.190.94]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 9B4D33F73D; Tue, 17 May 2022 02:06:17 -0700 (PDT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 9dedc3ff-d5c0-11ec-bd2c-47488cf2e6aa From: Penny Zheng To: xen-devel@lists.xenproject.org Cc: wei.chen@arm.com, Penny Zheng , Stefano Stabellini , Julien Grall , Bertrand Marquis , Volodymyr Babchuk , Penny Zheng Subject: [PATCH v4 5/8] xen/arm: Add additional reference to owner domain when the owner is allocated Date: Tue, 17 May 2022 17:05:26 +0800 Message-Id: <20220517090529.3140417-6-Penny.Zheng@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220517090529.3140417-1-Penny.Zheng@arm.com> References: <20220517090529.3140417-1-Penny.Zheng@arm.com> MIME-Version: 1.0 Borrower domain will fail to get a page ref using the owner domain during allocation, when the owner is created after borrower. So here, we decide to get and add the right amount of reference, which is the number of borrowers, when the owner is allocated. Signed-off-by: Penny Zheng Reviewed-by: Stefano Stabellini --- v4 changes: - no change --- v3 change: - printk rather than dprintk since it is a serious error --- v2 change: - new commit --- xen/arch/arm/domain_build.c | 62 +++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c index 59591e3c6e..3a20247836 100644 --- a/xen/arch/arm/domain_build.c +++ b/xen/arch/arm/domain_build.c @@ -794,6 +794,34 @@ static mfn_t __init acquire_shared_memory_bank(struct domain *d, } +static int __init acquire_nr_borrower_domain(struct domain *d, + paddr_t pbase, paddr_t psize, + unsigned long *nr_borrowers) +{ + unsigned long bank; + + /* Iterate reserved memory to find requested shm bank. */ + for ( bank = 0 ; bank < bootinfo.reserved_mem.nr_banks; bank++ ) + { + paddr_t bank_start = bootinfo.reserved_mem.bank[bank].start; + paddr_t bank_size = bootinfo.reserved_mem.bank[bank].size; + + if ( pbase == bank_start && psize == bank_size ) + break; + } + + if ( bank == bootinfo.reserved_mem.nr_banks ) + return -ENOENT; + + if ( d == dom_io ) + *nr_borrowers = bootinfo.reserved_mem.bank[bank].nr_shm_domain; + else + /* Exclude the owner domain itself. */ + *nr_borrowers = bootinfo.reserved_mem.bank[bank].nr_shm_domain - 1; + + return 0; +} + /* * Func allocate_shared_memory is supposed to be only called * from the owner. @@ -805,6 +833,8 @@ static int __init allocate_shared_memory(struct domain *d, { mfn_t smfn; int ret = 0; + unsigned long nr_pages, nr_borrowers, i; + struct page_info *page; dprintk(XENLOG_INFO, "Allocate static shared memory BANK %#"PRIpaddr"-%#"PRIpaddr".\n", @@ -819,6 +849,7 @@ static int __init allocate_shared_memory(struct domain *d, * DOMID_IO is the domain, like DOMID_XEN, that is not auto-translated. * It sees RAM 1:1 and we do not need to create P2M mapping for it */ + nr_pages = PFN_DOWN(psize); if ( d != dom_io ) { ret = guest_physmap_add_pages(d, gaddr_to_gfn(gbase), smfn, PFN_DOWN(psize)); @@ -830,6 +861,37 @@ static int __init allocate_shared_memory(struct domain *d, } } + /* + * Get the right amount of references per page, which is the number of + * borrow domains. + */ + ret = acquire_nr_borrower_domain(d, pbase, psize, &nr_borrowers); + if ( ret ) + return ret; + + /* + * Instead of let borrower domain get a page ref, we add as many + * additional reference as the number of borrowers when the owner + * is allocated, since there is a chance that owner is created + * after borrower. + */ + page = mfn_to_page(smfn); + for ( i = 0; i < nr_pages; i++ ) + { + if ( !get_page_nr(page + i, d, nr_borrowers) ) + { + printk(XENLOG_ERR + "Failed to add %lu references to page %"PRI_mfn".\n", + nr_borrowers, mfn_x(smfn) + i); + goto fail; + } + } + + return 0; + + fail: + while ( --i >= 0 ) + put_page_nr(page + i, nr_borrowers); return ret; }